US4231076A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Tantalum foil capacitor with strong acid electrolyte
Assignee: Vishay Sprague Inc
•
Filing: 1978-09-27
•
Granted: 1980-10-28
•
Expires: 1998-09-27
Abstract
Abstract A low ESR tantalum foil electrolytic capacitor uses a 30-40 wt % sulfuric acid electrolyte and a porous, synthetic spacer material.
Inventors
- 👤 Mark Markarian
- 👤 Kenneth B. Meyer
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 22:59
CPC Classifications
H; H01; H01G; H01G9/00; H01G9/004; H01G9/02
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
103 words
A wound tantalum foil electrolytic capacitor comprising an anodized tantalum foil anode, a tantalum foil cathode, a porous chemically-resistant spacer sheet interposed between said anode and said cathode foils and wound contiguous therewith throughout the entire length of said foils, an aqueous 30-40 wt % sulfuric acid electrolyte in contact with said foils and said spacer throughout the winding, said spacer being chosen from the group consisting of microporous polypropylene film, porous perfluoroethylene cloth, polyolefin fiber paper, porous woven polypropylene, polypropylene screen, and porous woven glass cloth, said capacitor having a low equivalent series resistance and increased capacitance per given length of foil.
Claim 2
Dependent Claim
103 words
A wound tantalum foil electrolytic capacitor comprising an anodized tantalum foil anode, a tantalum foil cathode, a porous chemically-resistant spacer sheet interposed between said anode and said cathode foils and wound contiguous therewith throughout the entire length of said foils, an aqueous 30-40 wt % sulfuric acid electrolyte in contact with said foils and said spacer throughout the winding, said spacer being chosen from the group consisting of microporous polypropylene film, porous perfluoroethylene cloth, polyolefin fiber paper, porous woven polypropylene, polypropylene screen, and porous woven glass cloth, said capacitor having a low equivalent series resistance and increased capacitance per given length of foil.
Claim 3
Dependent Claim
16 words
A capacitor according to claim 1 wherein said electrolyte initially is 40 wt % sulfuric acid.
Claim 4
Dependent Claim
19 words
A capacitor according to claim 1 wherein said spacer is a microporous polypropylene film or a woven glass cloth.
References Cited (Backward Citations)
CA834993A
Cited
JPS5138654A
Cited
US3908157A
Cited
FR2323217A1
Cited
US4099218A
Cited
US4151581A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1983-10-28 | 1984-04-28 | 1984-10-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1987-10-28 | 1988-04-28 | 1988-10-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1991-10-28 | 1992-04-28 | 1992-10-28 | $7700.00 | Window Closed / Lapsed |